Currently,i am working on magento 2,i need to integrate the worldpay payment gateway i done my extension installation, now i need to get the installation key, i also checking in world pay sandbox account and check there, i not able to find where it's present.
I think you are looking for the API key for the worldpay payment gateway. if you have an worldpay merchant account then login to your account click on the link to get the Api key Api keys for worldpay Also check this link for more information